This invention relates to a bridge of a ship and more particularly to an asymmetric bridge where the main navigation workstation is located aside the center line of the ship on the starboard side or on the port side of bridge.
When designing the bridge form for a ship the most important factors to be considered are the overall view required from the inside of the bridge and the field of vision required from each workstation. For safe navigation and maneuvering of the ship it is necessary that all objects of interest for navigation, such as ships, lighthouses, etc., can be seen in any direction from inside the wheelhouse.
The workstations for navigation and traffic surveillance/maneuvering are prescribed in the Det Norske Veritas regulations. Additionally, according to those rules, other workstations are needed such as:
workstations for conning; PA1 workstations for route planning; PA1 workstations for manual steering; PA1 workstations for docking; and PA1 workstations for performance of additional functions. PA1 workstation for navigation. PA1 workstation for traffic surveillance/maneuvreing PA1 workstation for manual steering; PA1 workstation for docking operations; PA1 workstation for conning; and PA1 workstation for performance of additional operations like PA1 to the reverse side of the ship ahead of the front bulkhead of the bridge in an angle abaft the beam, and/or PA1 to the stern and to the aft deck of the ship in the direction that forms an angle between the direction of the center line of the ship.
The bridge of the traditional merchant vessel is symmetric. Normally the main navigation workstation is located in the center of the bridge. The simple steering workstations may be added on both sides of the bridge at bridge wings for docking. This same arrangement is still used also on the bridge of the modern passenger ship.
In some cases like in the modern icebreakers the main navigation workstations are situated on both wings and a simple steering workstation is in the middle. This arrangement, however, is complicated and takes lots of room because all the systems must be duplicated.
To avoid double systems on the bridge the asymmetric bridges have been used. The main navigation workstation is in that case located asymmetrically on starboard side because of collision regulations. The vessels shall normally allow sufficient space for safe passing to the vessels coming from starboard side.
Modern research vessels have been equipped with asymmetric bridges because a long side wing provides a good visibility toward the stern of the ship. For the same reason some modern one man bridges for cargo ships have also been asymmetric.
However, modern asymmetric bridges also have disadvantages. The asymmetric bridge form considerably limits the view seen from the main navigation workstation. To fulfill the requirements for the field of vision according to the international rules and for example Det Norske Veritas rules for one man bridge regulations the different workstations must be located in the different parts of the bridge. The view from the bridge is also limited by the superstructures, funnels and stairways which limit sight especially aftship.
Besides for navigation and maneuvreing the sight aft and around the ship is also needed when working for example on the work deck aft, on the helideck, by the side doors, on rescue equipment area and with the research equipment, etc. Good aft and around sight also makes it possible to control the deck equipment like cranes, winches, research equipment etc. It also reduces the manning at the bridge and adds cooperation in different operations even in that amount that the often used aft wheelhouse can be left away.
By using the asymmetric bridge design it is possible to gain sight which is superior compared to the present bridge design. It is also possible to concentrate many operations to be controlled by one main workstation on the starboard side. The consequences are that the manning on the bridge can be reduced. Due to the good sight at least the following workstations at the bridge can be combined:
crane and winch controls PA2 dynamic positioning control PA2 research equipment control PA2 helideck control PA2 work deck operations control, etc.
Normally only a secondary docking workstation on the port side is needed for harbour operations and for special operations.
The unobstructed sight has been achieved by placing the main workstation as far as possible away from all obstructing structures like stairways, lift if used, funnel etc. which will be located on the port side corner of the bridge. By this arrangement the blind sector will be minimized.
Also by forming the bridge bulkheads in line in the direction of sight so that they widen toward the comer where the obstructions are the excellent sight can be achieved. Also by placing all the extra workstations like the workstation for safety operations, for radio, for machinery and for navigation into this blind sector this superior field of sight has been made possible.
The best results for the good sight close to the vessel can be achieved by also having an at least partly asymmetric deckhouse.